NASA to launch Endeavour's final mission on May 16

WASHINGTON: The date for the launch of NASA's space shuttle Endeavour has been finalised for May 16.

NASA managers have set the lift-off for 8:56 a.m. EDT on Monday. Launch attempts are available through May 26, except for May 21. The STS-134 mission to the International Space Station is the penultimate shuttle flight and the final one for Endeavour.

Space Shuttle Program Launch Integration Manager Mike Moses and Shuttle Launch Director Mike Leinbach also discussed the progress of repairs since Endeavour's launch postponement on April 29 at a news briefing from NASA's Kennedy Space Center in Florida.

A short in the heater circuit associated with Endeavour's hydraulic system resulted in the launch postponement. Technicians determined the most likely failure was inside a switchbox in the shuttle's aft compartment and associated electrical wiring connecting the switchbox to the heaters. The heater circuits prevent freezing of the fuel lines providing hydraulic power to steer the vehicle during ascent and entry.

The faulty box was replaced May 4. Since Friday, Kennedy technicians installed and tested new wiring that bypasses the suspect electrical wiring and confirmed the heater system is working properly. They also are completing retests of other systems powered by the switchbox and are closing out Endeavour's aft compartment. 

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Endeavour Power Box Testing Continues, New Launch Date Expected Friday

Technicians at NASA Kennedy Space Center’s Launch Pad 39A in Florida continue testing various systems inside space shuttle Endeavour associated with a newly installed power distribution box, called a Load Control Assembly 2 (LCA-2). So far, all systems have checked out. Overnight, teams will retest power for Endeavour’s reaction control system.



Endeavour’s no earlier than launch date remains May 10, but senior NASA managers will meet Friday to evaluate the progress of repairs and select a new launch date for the STS-134 mission to the International Space Station.



Engineers have been doing forensic engineering testing on the failed LCA-2, which was removed from Endeavour on Tuesday. The LCA-2 feeds power to a variety of systems, including heaters on the fuel line for Endeavour’s auxiliary power unit-1 (APU-1). APUs control the shuttle’s hydraulic system. Teams are trying to determine what caused a circuit inside the power box to short out.


‪The APU-1 fuel line heaters did not work on April 29, prompting the launch team to scrub Endeavour’s first launch attempt.

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NASA says Endeavour will not launch before May 10

• WASHINGTON - Engineers have identified the technical problem that delayed the space shuttle Endeavour's final mission last week, but the next liftoff attempt will not be before May 10, NASA said Monday.
  
  "NASA space shuttle and International Space Station managers met Monday and determined that Tuesday, May 10 is the earliest Endeavour could be launched on the STS-134 mission," the US space agency said in a statement.
  
  The mission of the shuttle Endeavour is to be the US program's second-to-last flight to the International Space Station, followed by Atlantis in June. After that, the 30-year-old US shuttle program will end.
  
  The glitch, which caused NASA to scrub the attempt hours before liftoff Friday, was traced to a power problem in the aft load control assembly-2 (ALCA-2), a box of switches that control electrical flow to heaters that keep fuel lines from freezing in orbit.
  
  "The plan is to remove and replace the box, but that work and related testing will take several days to complete," NASA said.
  
  "Plans are for managers to reconvene Friday to determine a more definite launch date after the box is removed and replaced and the retest of systems has been completed."
  
  The six-member crew of astronauts left Florida on Sunday and are engaging in more mission training at NASA's Johnson Space Center in Houston, Texas while they wait for the next launch attempt date to be announced.
  
  Endeavour will carry a $2 billion, seven-ton particle physics detector, the Alpha Magnetic Spectrometer-2, which will be left at the space station to scour the universe for dark matter and antimatter.
  
  The 14-day mission, known as STS-134, is to be commanded by US astronaut Mark Kelly, whose wife, Arizona Congresswoman Gabrielle Giffords, is recovering from a gunshot wound to the head sustained in January.
  
  Giffords was allowed by her rehab doctors in Houston to fly to Florida to watch the launch, and she is expected to return again for the next attempt, her office said.

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